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1、INTERNATIONAL STANDARD 4297 lNTERNATlONALORGANIZATION FOR STANDARDIZATIONMEYHAPOAHAR OPtAHH3AUHR ROCTAHRAFW3AUblWORGANlSATlON INTERNATIONALE DENORMALISATION Manganese ores and concentrates - Methods of chemical analysis - General instructions Minerais et concent the second, the number of parts by vo
2、lume of water. 3.1.7 The concentrations of solutions are expressed in one of the following forms : a) % (m/m), meaning the mass, in grams, of component in 100 g of solution; b) g/l, meaning the number of grams of component in 1 litre of solution; c) % (V/V), meaning the volume, in millitres, of com-
3、 ponent in 100 ml of solution. 3.1.8 In each run, the standardization of a standard volumetric solution shall be carried out by not less than three titrations. 3.2 Apparatus 3.2.1 .Weighing shall be carried out on an analytical balance to the nearest 0,000 2 g. 3.2.2 The weighing device and laborato
4、ry measuring equipment (pipettes, burettes, volumetric flasks, thermometers, etc.) shall be verified and appropriate corrections shall be made during the calculation of the analytical results. 3.23 Cells for measurement of the absorbance of coloured solutions shall be chosen so that measurements may
5、 be carried out in the optimum range of absorbance. 33 SampleI) - Analysis shall be carried out on an air-dried sample or the sample dried at 105 to 110 “G. 1) International Standards on sampling of manganese ores, and on the preparation of samples, are in preparation. 1 Copyright International Orga
6、nization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 21:33:34 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 4297-l 978 (El 3.4 Pracedure 341 Number of testportions To determine th
7、e content of a particular element in a manganese ore or concentrate, two test portions (or three, if specified in the relevant International Standard, or by agreement between the interested parties) shall be analysed simultaneously. The arithmetic mean of the values obtained from the duplicate analy
8、sis of the test sample shall be accepted as the final result. The range of the values obtained shall not exceed the limits of permissible tolerance for the corresponding range of the element content specified in the sub-clause entitled “Permissible tolerances on results of duplicate or parallel dete
9、rminations” in the relevant International Standard. When the range of the two values obtained from analysis of the test sample is outside the limits of permissible tolerance, the cause of this deviation shall be ascertained and eliminated and the determination shall be repeated on three new test por
10、tions. 3A.2 Blank test In parallel with the determination and under the same conditions, except as modified in the relevant International Sfandard, two blank tests shall be carried out so that the appropriate correction may be made to the result of the determination. 3A3 Check test In parallel with
11、the determination and under the same conditions, a check analysis shall be carried out on two test portions of a standard sample of manganese ore or concentrate taken from the same type of ore or concentrate as the test sample, The arithmetic mean of the values obtained from the duplicate analysis o
12、f the standard sample of manganese ore or concentrate shall not differ from the result shown in the certificate by more than half the value of the permissible tolerance for the corresponding range of the element content specified in the sub-clause entitled “Permissible tolerances on results of dupli
13、cate or parallel determinations” in the relevant International Standard. Otherwise, after elimination of the causes of such deviations, the analysis of the test sample and the standard sample shall be repeated. 3.4.4 Determination of hygroscopic moisture content In parallel with the determination, t
14、wo test portions shall be taken to determine the hygroscopic moisture content in accordance with IS0 310. For the determination of the phosphorus content, only one test portion shall be taken to determine the hygroscopic moisture content. To calculate the content of an element on the dry basis, the
15、numerical result of the determination shall be multiplied by the conversion factor K calculated to the third decimal place from the formula K= b) reference to the relevant International Standard; c) results of the analysis; d) the reference number of the results; the e) any characteristics noticed d
16、uring the determination, and any operations not specified in the relevant International Standard, which may have had an influence on the results. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 21:33:34 MDTNo reproduction or networking permitted without license from IHS -,-,-